Rolling mill



Jan. 24, 1967 G. KNAP 3,299,684

ROLLING MILL Filed Oct. 28, 1963 2 Sheets-Sheet il INVEHTOR GEORGE KNAP Y MW /r TTORNEYG G. KNAP ROLLING MILL Jan. 24, 1967 2 SheetS-Sheet 2 Filed Oct. 28, 1963 AYTORNEYG United States Patent O 3,299,684 ROLLHNG MILL George Knap, 4408 Wildwood Crescent, South Burnaby, British Cournhia, Canada Filed Oct. 28, 1963, Ser. No. 319,132 2 Claims. (Cl. '72-198) This invention relates to rolling mills for reducing the cross sectional me-asurement of malleable stock, specifically stock of non-uniform size and shape.

In standard rolling mills, the rolls between which the stock is passed are usually formed with a series of paired annular grooves, each groove being yreduced in crosssectional measurement to provide a series of stationary passes consecutively decreased in cross-sectional measurements, whereby a bar of steel or the like may be run through each pass consecutively, thereby reducing its cross-sectional area. In this type of rolling mill, guides are usually required to align the bar blank With the appropriate pass through the rolling mill, and the Operators must be very experienced and adept in their use. It has also been found that this type of rolling mill is not suitable where the materials to be rolled are of various crosssectional shapes and sizes. The nip provided by the walls of the pass upon the stock to be rolled, is only effective where the dimensions of the pass are just a little smaller than the dimensions of the stock, otherwise the end of the stock will slide against the walls of the pass at the infeed side, preventing feeding of the stock between the rolls. Where the cross-sectional dimensions of the stock are such that one dimension is much greater than another, the stock material must be passed through the rollcrs an excessive number of times in order to reduce its cross-sectional area to workable proportions.

The .present invention provides a rolling mill which requires little, if any skill from an operatr, to feed the stock material to be rolled and furthermore reduces the number of passes required to reduce the cross-sectional area of any material fed therethrough. It may therefore be used most advantageously in handling stock, such as scnap ends, in which the material size and length vary greatly.

The present invention provides a rolling mill to reduce the cross-sectional area of malleable metallic stock comprising at least a pair of driven, axially parallel rolls in which at least one of the rolls is provided with 'an axially extending, helically wound groove in its rolling surface, said groove tapering from one end to the other, whereby upon rotation of the rolls the groove prevents a series of passes moving longitudinally of the rolls in steadily decreasng cross-sectional area.

The present invention also provides a stripping means located adjacent the rolls to release the roll stock in the event it is gripped by the grooves in the rolls and carried around said rolls.

In the drawings which illustrate the embodiments of the invention,

FIGURE 1 is a view in elevation of a three-high type mill showing the formation of grooves on the roll thereof,

FIGURES 2, 3 and 4 are fragmentary sectional views of a pass showing the manner in which it affects a piece'of stock material,

FIGURE 5 is an isometric view of one form of stripper,

FIGURE 6 is an isometric view of another form of stripper,

FIGURE 7 is a partial isometric view of yet another form of stripper,

FIGURE 8 is 4a partial isometric view of yet another form of strip-per,

FIGURE 9 is another form of three-high mill showing the formation of the grooves thereon, and

FIGURE 10 is an alternate form of mill of a two-high i sized hole in pass 23 `in which the bar is again nipped type showing the configuration of the grooves thereon.

Patented Jan. 24, 1967 ICC In the construction of rolling mills, the rolls are usually disposed one above the other in a Vertical framework so that the axis of each is parallel to the other and the rolling surfaces almost, but not quite, touch. The rolls are driven by a train of gears, themselves driven by a suitable source of power and each of the rolls has its rolling surface grooved or ridged to mate with similar grooves or ridges on the ladjacent roller. The mating grooves where they lie adjacent to each other at the point of tangency or passline of the mill, provide openings called passes into which metal of various shapes is fed, the walls of the passes deforming the cross-sectional shape of the stock passing therethrough, reducing said cross-sectional -area and elongating the stock material.

Mills may be composed of two, three or four rolls positioned one above the other and called either two-, threeor four-high mills, respectively. The two-high mill is able to pass stock material from one side thereof to the other, but the direction of rotation of this type of mill must be reversed to pass the stock back. This is not so with the three or four-high mills as the addition of the third roller provides -a lead-in on both sides of the mill. The stock material may, therefore, be passed back and forth from one side to the other of the mill, though gradually reduced, passes without reversing the direction of rotation of lthe rolls.

Referring now to the drawings and specifically to FIG- URE 1, which depicts one form of a three-high mill having an upper roll 11, a middle roll 12 and lower roll 13, said rolls having helical grooves 14, 15 rand 16, respectively, formed in their peripheral or rolling surfaces'and extending from one end 18 of the mill to the other end 19. The grooves 14 and 16` formed in rolls 11 and 13 respectively, each have the same pitch and each tapers in crosssectional measurement from end 18 to end 19. The groove 15 formed in middle roll 12 is of equal, but opposite pitch to grooves 14 and 16. It does, however, taper from end 18 of the mill to end 19 thereof in the same manner -as do grooves 14 land 16. All three rolls are rotatably positioned with respect to each other so that the grooves 14415 and 15-16 are in complementary relationship. It will be seen by referring to FIGURE 1, that the foremen` tioned complementary relationship results in a series of passes 22 consecutively reducing in cross-sectional area between end 18 and end 19 of the rolling mill, between rolls 11-12, and a similar series of passes 23 between rolls 12 and 13.

The rolls which are carried in a Vertical framework, not shown, -are rotated by a gear drive, not shown, in the customary manner so that rolls 11 'and 13 rotate in one direction whereas roll 12 rotates in the other. It will be seen that when the mill is viewed from one side thereof, the rolls are Vrotated so that passes 22 form the lead-in passes, passes 23 become outfeed passes, the reverse situation existing when the mill is viewed from the other side.

In the use of the rolling mill 10, assuming that the direction of rotation of the rolls is such that passes 22 form the lead-in passes, -a length of steel bar 25, the end 26 of which is shown in cross sectional aspect in FIGURES 2, 3 and 4, is inserted into any one of the passes 22 which is of sufficient size at the time of insertion, to slidably receive s-aid steel bar. The bar 25 is allowed to rest on groove 15 until the pass 22 has reduced in cross sectional area so that it nips the bar and commences to carry it through the roll. The ever reducing pass gradually deforms the har, as shown in FIGURES 3 and 4, gradually tapering it `as the pass moves towards end 19 of the rolls. After the tail end of the bar passes through the rolls, it is fed into a suitable between the rolls 12 'and 13 and the tapering process continued.

It will be realized that in the deforrnation of the steel bar as carried out by the passes, the bar will tend to be gripped by the grooves as it emerges from the outfeed side of the rolls and, if not released therefrom, might be -carried Iaround one of the rolls and gradually wrap itself around said roll in which event the direction of rotation -of the rolls must be reversed -and the bar pulled therefrom. In order to prevent this latter occurrence, the rolling mill 10 is provided with a stripper which is adapted to slide between the rolls and the emerging steel bar to prevent wrapping of the latter around one of the rolls.

One form 30 of a stripper is shown in FIGURE and comprises an endless chain 31 carried on a pair of sprockets 32 which are carried for free rotation on suitable shafts, not shown, said shafts being secured to any part of the framework of the rolling mill so that one side 33 of the chain is horizont-al and is d-isposed parallel with the longitudinal axis Vof the roll at its outfeed side. The chain is provided with a plurality of fingers 34 spaced along its length in intervals corresponding to the longitudinal distance between the grooves, said fingers having ends 35 adapted to slidably fit within the grooves. It will be seen that as the roll revolves, the fingers 34 will follow the groove therein, rotating the chain. of the mil-l, it will disengage itself from the groove to return to end 18 to again engage the groove. The fingers 34 lare adapted to slidably set themselves between the groove and the steel bar 25 Which may be gripped 'thereby to prevent the return of the bar around the roll.

Another form 40 of the stripper is shown in FIGURE 6, and comprises -a block 41 slidably supported on the outfeed side of the roll on a pair of longitudinally disposed horizontal slides 42. A pair of fingers 43 are secured at one end 44 thereof to the block and have their other ends 45 projecting outwardly towards the roller within the groove formed thereupon. The function of stripper 40 is exactly the same as that of stripper 30.

FIGURE 7 depicts yet another form of stripper 50, which comprises a blade-like member 51 held parallel to the longitudinal axis of the roll at the outfeed side thereof to slidably bear against the rolling surface thereof, s-aid blade-like member 51 being supported in end blocks 52 which are secured in a suitable manner to the frame, not shown, of the rolling mill 10. The blade member is the preferred form -of stripper and functions in the same manner as strippers 30v and 40. It may be noted that as the steel bar 2-5 is usually threaded through one of the passes so that an end portion thereof lies on the outfeed side of the rollers prior to the nip of the rollers against the bar 25, said end portion will not be gripped by the grooves in the roller and will, therefore, ride over bar member 51 to permit said bar member to lift the steel bar 25 from the grip of the groove.

FIGURE 18 depicts still another form of stripper 53. Stripper 53 is c-omprised of a plurality of gear-like members 54 having peripheral teeth 55, said members being mounted for rotation on a Supporting bar 56. The plane of rotation of each of the gear-like members 54 is parallel to the longitudinal axis `of the bar 56 and the bar 56 is secured to the Supporting roll framework, not shown, longitudinally of a helically igrooved roll 57 so that the axes of rotation of the.gear-like members lie laterally to the axis of rotation of the roll. The gear- 'like members 54 lare so arranged and the teeth 55 thereof are so spaced around the periphery of each of said members that each of said gear-like members 54 will rotate and intermesh with the hel-ically grooved roll 57 much in the same manner as a worm and worm gear. The stripping taction Iof the teeth 55 of the gear-like As each -of the fingers reaches the end 19 members is somewhat the same as described in the stripping as accomplished by strippers 30, 40 and 50.

FIGURE 9 shows another form of three-high mill 60 having upper, middle and lower rolls 61, 62 and 63, respectively, said rolls having helical grooves 64, 65 and 66 respectively, rformed -in their respective rolling surfaces in much the same manner as'rolling mill 10. The only difference between rolling mill 60 vand rolling mill 10, is the provision of annular grooves 67, 68 and 69 formed in each o-f rolls 61, 62 and 63, respectively, near their vends 70.

The annular grooves 67, -68 and 69 present complementary faces to each other to form a pair of constant area passes between each of said rolls. Helical grooves 64, 65 and 66 emerge int-o the annular grooves 67, 68 and 69, respectively, and provide a means whereby when the steel bar 25 is reduced at one end to a minimum cross sectional area -as determined by the size of the smallest pass, it may be passed through the annular groove which is of the same cross sectional size as said minimum size to thereby form the bar into a regular uniform shape corresponding to the cross sectional size of the passes provided by said annular grooves l67, 68 and 69.

FIGURE 10 shows a two-high rolling mill l80, having an upper roll 81 and lower Iroll 82. The upper roll 81 is provided with a first :axially extending helical groove 83 formed in its rolling surface and taperin-g from one end 85 of roller 81 to the other end 86 thereof. A second axially extending helical groove 88 having the same pitch as groove 83, is also formed in the rolling surface of roll 81 but tapers in a reversed direction to said groove r83. Lower roll 82 is provided with a pair of grooves 90 and 91 formed in the rolling surface thereof :and lhaving a pitch equal to but reversely to grooves 83 and 88. Groove 90 is tapered in the same direction as groove 83 and groove 91 in the same direction as 88. The rolls are rotatably pos-itioned so that grooves 83 and 90 complement each other at the line of pass similarly as do grooves 88 and 91. Referring to FIG- URE 9, it Will be seen that when the rolls v81 and 82 are rotated to roll upon one another so that grooves 83 and 90 form lead-in passes of gradually increasing cross sectional diameter, grooves 88 and 91 when viewed from the same side, produce a series of passes which gradually decrease in cross sectional diameter. However, when the direction of rotation of the` rolls is reversed, grooves 88 and 91 will present, from the other side of the rolling mill 80, a series of passes increasing in cross sectional diamete-r in the reversed direction.

In the use of rolling mill 80, the steel bar 25 may Ibe passed through one side to thereby reduce its cross sectional diameter. Ho-wever, the rolls must be reversed in their direction of rotation in order that the bar 25 may be inserted into the passes from the other side of the rolling mill to thereby reduce its cross sectional measurement.

The annular grooves 67, 68 and 69 as described in rolling mill 60 may also be used in rolling mill 80.

What I claim as my invention is:

1. A rolling mill to reduce the cross sectional area of malleable metallic stock comprising at least a pair of driven, axially parallel rolls, a first axially extending, helically wound groove formed in each of the rolls, said grooves having equal .and opposite pitch .and tapering in the same direction, a second axially extending, helically wound groove .formed in each of the rolls parallel to the first groove therein and tapering in an opposite direction to said first groove, said rolls being rotatably positioned relative to each other so that the said first and second grooves in one of said rolls is mated With the corresponding first and second grooves in the other roll, at the line of pass, whereby upon rotation of the rolls in one direction, the first grooves present, from one side of the mill, a series of passes moving longitudinally of the rolls in steadily decreasing cross sectional area and upon reversng the direction of rotation of the rolls the second groovcs present, from the other side of the mill, a similar series of longitudinally moving passes.

2. A rolling mill to reduce the cross sectional area of malleable metallic stock compirising at least a pair of driven, axially parallel rolls provided with axially extending helcally Wound matching grooves of equal and opposite p-itch, each of said grooves tapering from one end to the other, said rolls being rotatably positioned relative to each other so that the grooves present complementary faces at the line of pass whereby upon rotation of the rolls the grooves present a series of passes moving longitudinally of the rolls in steadily decreasing cross sectional area, and stripping means at the outfeed side of the rolls, said stripping means comprising an endless fbelt supported to move longitudinally of a roll from Which the lead-in of the stock is to be stripped, and laterally extending finger members spaced along the belt and slidably bearing on the roll in the groove therein so as to extend between the lead-in of the stock being rolled :and the `roll.

References Cited by the Examiner UNITED STATES PATENTS 252,464 1/ 1882 Holub 72-221 335,910 2/ 1886 Foulks 72-221 750,042 1/1904 Worth 72-221 797,221 8/1905 Price et al. 72-186 1,735,746 11/1929 Geer 72-35 2,377,9180 6/ 1945 Surerus 72-2211 2,780,948 2/ 1957 Fredriksson 72-221 CHARLES W. LANHAM, Primary Examner.

R. J. HERBST, Examiner. 

1. A ROLLING MILL TO REDUCE THE CROSS SECTIONAL AREA OF MALLEABLE METALLIC STOCK COMPRISING AT LEAST A PAIR OF DRIVEN, AXIALLY PARALLEL ROLLS, A FIRST AXIALLY EXTENDING, HELICALLY WOUND GROUND FORMED IN EACH OF THE ROLLS, SAID GROOVES HAVING EQUAL AND OPPOSITE PITCH AND TAPERING IN THE SAME DIRECTION, A SECOND AXIALLY EXTENDING, HELICALLY WOUND GROOVE FORMED IN EACH OF THE ROLLS PARALLEL TO THE FIRST GROOVE THEREIN AND TAPERING IN AN OPPOSITE DIRECTION TO SAID FIRST GROOVE, SAID ROLLS BEING ROTATABLY POSITIONED RELATIVE TO EACH OTHER SO THAT THE SAID FIRST AND SECOND GROOVES IN ONE OF SAID ROLLS IS MATED WITH THE CORRESPONDING FIRST AND SECOND GROOVES IN THE OTHER ROLL, AT THE LINE OF PASS, WHEREBY UPON ROTATION OF THE ROLLS IN ONE DIRECTION, THE FIRST GROOVES PRESENT, FROM ONE SIDE OF THE MILL, A SERIES OF PASSES MOVING LONGITUDINALLY OF THE ROLLS IN STEADILY DECREASING CROSS SECTIONAL AREA AND UPON REVERSING THE DIRECTION OF ROTATION OF THE ROLLS THE SECOND GROOVES PRESENT, FROM THE OTHER SIDE OF THE MILL, A SIMILAR SERIES OF LONGITUDINALLY MOVING PASSES. 